The invention is in the field of mechanical engineering, in particular microengineering, and relates to conveying blades for rotors of fluid pumps which are particularly suitable for use in areas which are difficult to access.
Such pumps can be configured so small as micropumps in medical engineering, for example, that they can be introduced into blood vessels with microinvasiveness. They can then be used for assisting the pumping force of the human heart.
To make such pumps advantageously deployable, they are often designed compressible and expandable so that they can be introduced in a compressed state through a blood vessel, for example up to and into a ventricle, and can be expanded there.
Provision is often made for this purpose that a corresponding rotor of the pump which can be driven very fast in operation is radially changeable, i.e. compressible and expandable between the transport state and the operating state.
Similar applications are, however, also conceivable in the non-medical area with larger pumps which should be used in regions difficult to access.
A plurality of such pumps are already known, with different principles being used to achieve compressibility. It is known from WO 98/53864 to use an axial flow pump having a rotor, wherein the rotor has the form of a rigid tube which is externally journalled in a stator. In this respect, the drive can be directly integrated into the stator and the rotor as an electromagnetic drive.
A pump having a compressible rotor is, in contrast thereto, known from WO 03/103745 A2, wherein the rotor with this pump has an unfoldable rotor blade which unfolds in operation due to the fluid pressure of the blood.
A pump is known in WO 2006/051023 having a rotor which has two cover surfaces and centrifugal blades disposed therebetween. The cover surfaces are pivotably fastened to the hub by means of joints.